Because of the flu outbreak and the declaration of a health emergency in Boston, the Archdiocese of Boston Thursday afternoon instructed priests that they can suspend the distribution of wine during Communion from a common chalice out of “pastoral caution and prudence.”

Auxiliary Bishop Robert P. Deeley also notified priests that may encourage worshipers to exchange the “Sign of Peace” by bowing to nearby parishioners instead of shaking hands.

Archdiocese spokesman Terrence Donilon said in an e-mail that Communion hosts will continue to be given because “it is central to the celebration’ of Mass. But priests will “use extra caution if people receive (the host) on the tongue and are to use extra caution in washing their hands before and after Mass.”

Normal practices will resume at the conclusion of the flu season, Deeley wrote.

The last time the Archdiocese implemented such safety measures was during the H1N1 “swine flu” outbreak in 2009.